The Legendary Centaur
was a beast with the head and torso of a man and the body of a horse. In Greek mythology, centaurs were the only monsters of old capable of doing good deeds, although some were rude, got drunk at weddings and celebrations, and broke the furniture. One of the noble and wise among these creatures was Chiron, son of Chronos and the ocean nymph Philyra. He was a mentor to many of the gods and heroes of Mount Olympus and the favorite teacher of both Apollo and Diana. The kindly Chiron was accidentally wounded by a poisoned arrow shot by Hercules, one of his pupils. On his death, Chiron was memorialized by Jupiter, who placed him among the stars as the constellation Centaurus, although some claim he is Sagittarius, the archer.

The constellation is a large southern one with only its northernmost stars visible to those on the mainland of the United States. But for people living in Hawai‘i Centaurus is one of the glorious features of spring skies. The only constellation other than Orion that has two first-magnitude stars, it is a star group that can easily be visualized as the creature it represents, prancing toward the east, over the Southern Cross, its forefeet studded with those bright stars, Alpha- and Beta-Centauri. The brighter of these two stars is a triple star system, a double that can be resolved with a small telescope, plus a third member which was discovered in 1915. This minor sibling in the Alpha-Centauri family revolves about the others in a very large orbit such that for part of its period it is the closest star to the Sun. It is thus named Proxima Centauri. The proximity of the entire system was known as early as 1839 when Thomas Henderson, director of the Cape Observatory in South Africa, measured its parallax to be nearly one second of arc (more exact measurements later brought this value down to 0.76"). This confirms that the distance to the star is 4.3 light-years. Only a very few stars are located close enough to us to make this direct method of triangulation, using the diameter of Earth’s orbit as the base, practicable for judging stellar distances.

There are no Messier objects in Centaurus, for Messier did not observe from a latitude from which the constellation could be seen. There are a number of objects there that would have made his list, including the largest and richest globular cluster in the entire sky, Omega Centauri. This was discovered to be a cluster by Halley, who viewed it from St. Helena in 1677 (Latitude 16°S).
This marvelous photo of the southern portion of Centaurus, together with Crux and parts of Carina, Vela, Musca and Circinus, was taken on March 26, 1998, by Axel Mellinger from the Cederberg Observatory in South Africa. He used a Minolta 50-mm lens at f/4, with Kodak Ektapress Multispeed PJM film.
At the left of the image Alpha and Beta-Centauri dominate, while at the center is the Southern Cross, just below and to the left of which lies the dark area known as the Coalsack. On the right is the beautiful Eta Carina Nebula. Please find a remarkable collection of Axel's work at his site: http://moore4.cchem.berkeley.edu/~axel/.
Another observer of the wonders of Centaurus was Herschel. He was first to sketch the curious galaxy known as Centaurus A. This is NGC 5128, referred to as an astronomical mystery waiting to be solved. It is the third brightest radio source in the sky, a giant spherical galaxy encircled by a dark dust band.

On May 14, 1998, NASA released images of Centaurus A, showing unprecedented detail in the dust lane. The Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) probed deeper, piercing the dust and revealing two powerful radio jets emerging from the core, which astronomers believe indicates that a massive black hole lurks there.

This image and others, together with a full description, can be found at http://oposite.stsci.edu/pubinfo/pr/1998/14/pr.html
Astronomers expected to find a dusty disk of gas feeding the black hole and oriented perpendicular to the jets, but instead they found a disk at a skewed angle. Perhaps new material is falling toward the black hole from different directions than before, creating the tilted disk that feeds into a smaller, unseen disk with the proper orientation.

A number of multiple stars, clusters and galaxies are in the realm of Centaurus, but because of their southerly position, they are usually not prime targets for amateur stargazing.

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